KIEV - A day ahead of a NATO summit, Ukraine issued a vague statement Wednesday about agreeing with Russian President Vladimir Putin on cease-fire steps for eastern Ukraine. The Russian-backed rebels rejected the move, saying no cease-fire was possible without Ukraine withdrawing its forces.

The back-and-forth came as President Barack Obama arrived in Estonia in a show of solidarity with NATO allies who fear they could be the next target of Russia's aggression. NATO is holding a summit in Wales on Thursday, with plans to approve a rapid-response team to counter the Russian threat.